一个环R称为quasi-normal环,是指对每个e∈E(R),a∈N(R),ea=0,总有eRae=0.证明了:①R是quasi-normal环当且仅当对每个e∈E(R),eR(1-e)Re=0;②设R是quasi-normal环,σ是环R的环满同态且保持幂等元不变,则R[x,σ]/(x2)是quasi-normal环,并且得到一些相关推论.
In this paper, it is shown that: ①Ring R is a quasi-normal ring if and only if for all e∈E(R), eR(1-e)Re=0;② Let R be a quasi-normal ring with a ring endomorphism a such that σ(e)=e for all e∈R. Then R[x,σ]/(x^2) is a quasi-normal ring. Some related results are also given.